MODULE AND SENSOR MODULE

FIELD OF INVENTION

The invention relates to an arrangement for performing a measurement. Additionally, the invention relates to an RFID module and a sensor module usable in the arrangement.

BACKGROUND

Arrangements are known from the prior art for e.g. measuring conditions of environment with sensors, the measurement data of which is read with an RFID function. Often the RFID function is integrated directly to sensor performing the measurement, such as in the solution disclosed in publication US 2005/0248455A1 , in which the solution includes a sensor and an RFID transponder, i.e. a transmitter for transmitting a characterizing ID. Alternatively, the sensor can be connected to an RFID unit with a separate control module, such as in the solution disclosed in publication US 2007/0109121 A1 , or by connecting with wired or wireless manner. However, some problems are related to the prior art solutions. For example, an RFID sensor is typically restricted to measuring just certain quantities, like e.g. an acceleration sensor only measures acceleration and an RFID pressure sensor only measures pressure. In targets, where several quantities must be measured, several separate RFID sensors are thus needed. This may bring a problem relating to limitations of the frequency band assigned to the RFID technology. Additionally, simultaneous usage of several RFID functionalities causes higher energy consumption. In a wide usage, this is a negative feature also for environment. It may also appear to be a problem to add RFID sensors which measure other quantities to a system at a later stage if the system already includes RFID sensors because the RFID functionalities of the RFID sensors may differ from each other. SUMMARY OF THE INVENTION

It is an objective of the invention to provide such a solution in which the above mentioned problems of the prior art can be reduced. Especially, the invention aims to solve how a system with measurement sensors could be easily modified for different kinds of measurement purposes.

The objectives of the invention are obtained with an RFID module and a sensor module, wherein the RFID module has data transfer means, memory means, a power supply (power source) and interface means. Additionally, the RFID module also has a microcontroller, which functionally intercon- nects the data transfer means, memory means, power supply and the interface means and controls their operation. The sensor module has a sensor for measuring at least one quantity, interface means and a microcontroller, which functionally interconnects the sensor and the interface means and controls their operation. In accordance with the invention, the interface means of the RFID module and the sensor module are both physically and functionally compatible with each other. Further, the RFID module and the sensor module have been adapted into a detachably connectable functional modular structure through said interface means in such a manner that the sensor module is adapted to deliver data measured by the sensor to the RFID module via the interface means, and the RFID module is further adapted to deliver said data measured by the sensor through a short range data transfer connection.

The arrangement according to the invention is characterized by what is disclosed in the characterizing part of claim 1. The RFID module according to the invention is characterized by what is disclosed in the characterizing part of claim 7.

The sensor module according to the invention is characterized by what is disclosed in the characterizing part of claim 10.

Some preferable embodiments are disclosed in the dependent claims. The RFID module is most preferably an active RFID module, which has an internal current supply, and its data transfer means is preferably a receiver/transmitter means based on data transfer on radio waves. With an inter- nal power supply it is possible to achieve a larger operating radius compared to a passive module. An internal power supply also makes it possible to provide an extended functionality, including the storage of data in an internal memory of an RFID module (such as ROM, WORM). An active RFID module has also typically a longer operating range and a larger memory means than passive modules. Additionally, active RFID modules may also store data transmitted by the receiver/transmitter into memory means.

According to one embodiment the RFID module is adapted to provide current to a sensor module which has been connected to the interface means of the RFID module. The current supply of the RFID module may be e.g. a changeable, disposable battery or a rechargeable battery. The current delivery feature of the invention offers clear advantages, such as that a current supply is required in just one module. It is preferable to provide the current supply in the RFID module especially if, according to one embodiment, the sensor module does not function independently but requires an RFID module and its data transfer means for external reading and transferring the data measured by the sensor.

According to one embodiment of the invention the sensor module also comprises at least one second interface means, whereby said sensor module can be connected with at least one second sensor module, which has compatible interface means for connecting the sensor modules detachably. This kind of a sensor module is preferably adapted to provide current from an RFID module connected to the sensor module to said second sensor module. On the other hand, the sensor module according to the embodiment of the invention is adapted to convey data measured by the second sensor module to the RFID module via said interface means.

According to one aspect of the invention several sensor modules can be connected to each other. In this case sensor modules are adapted to deliver current from the RFID module to a next further sensor module connected to the sensor module via interface means. On the other hand, sensor modules are also adapted to convey measurement data of a sensor of a further sensor module for delivering the data to the RFID module through said interface means.

According to one embodiment of the invention an RFID module comprises location means, such as a GPS receiver, whereby the location information is achieved in the RFID module independently on the type of the used sensor module. Thus RFID module may, according to one embodiment, function independently as an active RFID tag, delivering e.g. only location data and ID data, by which the RFID module can be identified. In a sensor module according to the invention the sensor can be any sensor according to prior art, such as a sensor which is adapted to measure temperature, pressure, illumination, acceleration, intensity of radiation, infrared radiation, humidity, magnetic field or sound, for example. However, these are just examples, and a sensor module according to the invention is not li- mited to these, but a person skilled in the art can replace the sensor with any known sensor without changing the inventive idea.

According to one preferable embodiment the sensor modules are both structurally and in their electric interface features similar so that it is possible to form a structure of sensor modules wherein all necessary sensors/sensor modules are connected to an RFID module.

The invention thus offers clear advantages compared to prior art solutions. For example, in planning the arrangement it is not necessary to know which all quantities are required to be measured with the arrangement, but according to the invention several sensor modules can be linked to each other, whereby at least one of the sensor modules is linked with the RFID module. For example, sensor modules with different kinds of sensors can be freely added and removed without a need for a specific configuration or programming the arrangement. Additionally, the connection of the modules is made with standard type interface means with a "plug and play" principle. Said in- terface means preferably functions both as a mechanical and electrical element connecting the modules, through which interface e.g. the data transfer from one sensor module to another and further to an RFID module is adapted to be made. According to one preferable embodiment the modules can be connected and disconnected with each other manually without tools. According to the invention the interface means have been adapted e.g. physically such that by connecting two modules to each other, such as an RFID module with a sensor module, or a sensor module with another sensor module, it is possible to provide a both functionally and structurally uniform modular entity. In this kind of a modular structure the modules can be com- bined functionally and physically without a need for any separate cables or wiring between the modules, but the electrical connection, i.e. data transfer and power supply, as well as the physical connection can be implemented through said interface means which are arranged with a fixed attachment in the modules. The arrangement according to the invention also requires and uses less frequency band for data transfer because it is possible to use even just one RFID module and thus only one frequency band (such as 868 MHz), whereby it is also more simple to read the data from the arrangement when compared to using several RFID tags. The enclosure of the RFID module preferably substantially encloses other parts of the RFID module. However, this means that the enclosure still has functionally required apertures for interface means, for example. The enclosure of the sensor module preferably substantially encloses other parts of the sensor module. However, this means that the enclosure still has func- tionally required apertures for interface means, for example, and possibly for the sensor in order to facilitate sensing the quantity to be measured from the environment. The enclosures of the modules facilitate an easy assembly of the measurement arrangements and protect the electronics of the modules.

BRIEF DESCRIPTION OF FIGURES

In the next part preferable embodiments of the invention are disclosed in more detail with reference to the enclosed Figures, wherein

Figure 1 illustrates an exemplary arrangement comprising an RFID module and a sensor module according to a preferable embodiment of the invention,

Figure 2 illustrates an exemplary sensor module structure according to a preferable embodiment of the invention, and

Figure 3 illustrates an exemplary arrangement, which comprises several sensor modules according to a preferable embodiment of the present invention. DETAILED DESCRIPTION OF FIGURES

Figure 1 illustrates an exemplary arrangement 100 comprising an RFID- module 101 and a sensor module 1 1 1 for performing a measurement in accordance with a preferable embodiment of the invention. The RFID module 101 of the arrangement comprises an enclosure 102, a data transfer means 103 supported by the base for providing short range data transfer connection memory means 104, current supply 105, such as e.g. changeable battery or rechargeable battery, and interface means 106. According to one embodiment the data transfer means 103 is a radio re- ceiver/transmitter. Additionally, the RFID module also comprises a microcontroller 107, which functionally connects the data transfer means 103, the memory means 104, the current supply 105, and the interface means 106, as well controls their operation in such a way that it is possible to provide data transfer from the interface means 107 to the memory means 104 and/or to data transfer means 103, as well as data transfer from the memory means 104 to the data transfer means 103. Further, the microcontroller 107 may also control current supply to the components of the RFID module and especially the current supply from the current supply to the interface means 106. By the control of the power supply it is possible, for example, to switch off power from certain components on selected time periods in order to reduce average power consumption of a module/modules.

The enclosure of the RFID module preferably substantially encloses other parts of the RFID module. However, this means that the enclosure still has functionally required apertures for interface means, for example. The sensor module 1 1 1 comprises an enclosure 1 12, a sensor 1 18 supported by the base for measuring at least one quantity 120, such as illumination, pressure, temperature or magnetic field, however, without any restriction to these. Additionally, the sensor module 1 1 1 comprises interface means 1 16 and a microcontroller 1 16 for controlling the measurement pro- cedures and data transfer, for example. The microcontroller may also control current supply bye e.g. performing measurements in a non-continuous manner and switching off the power from the sensor during other periods.

The enclosure of the sensor module preferably substantially encloses other parts of the sensor module. However, this means that the enclosure still has functionally required apertures for interface means, for example, and possibly for the sensor in order to facilitate sensing the quantity to be measured from the environment.

The interface means 106, 1 16 of the RFID module 101 and the sensor module 1 1 1 are both physically and functionally compatible with each other so that the RFID module and the sensor module can be connected to each other detachably, preferably manually without any tools, into a unitary functional module entity via the interface means 106, 1 16. The sensor module 1 1 1 is adapted to convey the data measured by the sensor 1 18 to the RFID module 101 through said interface means 106, 1 16. The data transfer from the sensor 1 18 to the interface means 1 16 is preferably controlled by the microcontroller 1 17 of the sensor module 1 1 1. The RFID module 101 is further adapted to transmit said data measured by the sensor 1 18 via short range data transfer connection by using data transfer means 103, such as radio receiver/transmitter, for example.

It should further be noted that the RFID module 101 is adapted to supply current to said sensor module 1 1 1 from the current supply 105 of the RFID module 101 via interface means 106, 1 16. In the sensor module 1 1 1 the microcontroller 1 17 preferably controls the current supply from the interface means 1 16 to the sensor 1 18 measuring a quantity.

According to one embodiment of the invention the RFID module 101 may also comprise location means 108, whereby the arrangement obtains location information independently of the type of the sensor module 1 1 1. However, it should be noted that the location means is an optional alternative, and that the idea to combine an RFID module and a sensor module into a functional entity can also be implemented without location means. It should further be noted that the RFID module may comprise an ID data, whereby it can be identified, and the data delivered by the RFID module can be combined with the exact arrangement comprising said RFID module. Figure 2 illustrates an exemplary sensor module structure 1 1 1 a, 1 1 1 b according to a preferable embodiment of the present invention, wherein the sensor module 1 1 1 a, 1 1 1 b comprises at least one second interface means 1 19a, 1 19b in addition to a first interface means 1 16a, 1 16b. By using the interface means 1 16a, 1 16b, 1 19a, 1 19b it is possible, for example, to con- nect the sensor module 111a with both an RFID module and with at least one second sensor module 111 b, as illustrated in Figure 3.

Figure 3 illustrates an exemplary arrangement 300 according to a preferable embodiment, which arrangement comprises several sensor modules 111a, 111b, and wherein a first sensor module 111a is connected physically and functionally to an RFID module 101 with interface means 106, 116a. Additionally, the first sensor modulel 11a is connected physically and functionally to a second sensor module 111b through interface means 119a of the first sensor module 111a and through interface means 116b of the second sen- sor module 111b. It is clear that it is possible to connect still some third sensor module to the sensor module 111b. According to the general idea of an embodiment of the invention it is possible to chain several sensor modules 111 to each other.

In the arrangement 300 the RFID module is adapted to supply current to the sensor module 111a through interface means 106, 116a which connect these modules. The current supply may be controlled by the microcontroller 107. Additionally, the sensor module 111a is adapted to supply current to the second sensor module 111b through interface means 119a, 116b, which connect said sensor modules 111a, 111b. The first sensor module 111a is further adapted to convey data measured by the sensor 118b of the second sensor module 111b to the RFID module 101 both through interface means 119a, 116b connecting the sensor modules 111a, 111b , and through interface means 106, 116a connecting the first sensor module 111a and the RFID module 101. This data transfer is preferably controlled by the micro- controllers 107, 117a, 117b. It should be noted that, according to an embodiment of the invention, each chained sensor module can be adapted to function according to the sensor module 111a serving as an intermediary both in supplying current and in conveying measurement data.

The RFID module 101 is adapted to receive data measured by the sensor 108a of the sensor module 111a, which sensor module is connected to the RFID module. The RFID module is also adapted to receive from the sensor module 111a measurement data supplied by another sensor module 111b. The measurement data supplied by the sensor module 111b can be data measured by a sensor 108b of the sensor module 111b and/or the mea- surement data may be supplied by some third sensor module which is con- nected to the sensor module 1 1 1 b. The reception of the data to the RFID module is preferably controlled by the microcontroller 107.

The RFID module 101 may, under the control of the microcontroller 107, store at least part of the received measurement data into memory means 104 and/or deliver it via the data transfer means 103, for example, to external party which may read the data. According to one embodiment, the RFID module may also deliver ID data and/or location data if the RFID module 101 also comprises location means 108, such as a GPS receiver.

According to the arrangement 300 of Figure 3 the measurement arrange- ment can be extended by connecting several sensor modules 1 1 1 a, 1 1 1 b, to each other, such as sensor modules measuring different quantities/magnitudes 120a, 120b. The sensor module 1 1 1 a may comprise, for example, a pressure sensor 1 18a for measuring pressure and the sensor module 1 1 1 b may comprise, for example, a temperature sensor 1 18b for measuring temperature.

Above, only some embodiments of the solution according to the invention have been described. The principle of the invention can naturally be modified within the scope of protection defined by the patent claims, for example, relating to the details of the implementation and areas of use. It should especially be noted that even if all bases 1 12, 1 12a, 1 12b of the sensor modules are shown as same size, the size of the base does not have meaning in terms of the general idea of the invention. It is thus possible, for example, to provide larger bases for larger or special purpose sensors, which still have the interface means and other components and functions accord- ing to the present invention. It should also be noted that according to one embodiment a sensor module may comprise more than one sensor. Also in this case, in terms of the general idea of the invention, it is essential that the sensor module comprises interface means according to the invention as well as other components and functions.